Suggested as a device to support driving of a vehicle such as a car is an image processing device for taking an image of the face of the driver with an in-vehicle camera, which is arranged at a location capable of taking an image of the face of the driver, and performing image processing to detect the location of the facial contour and the eyes of the driver from an obtained image (see Patent Document 1, for example). By using such a device, it is also possible to construct a system for detecting the status of the driver and providing driving support such as warning depending on the status of the driver such as inattentive driving or drowsy driving. It should be noted that an automatic gain function of an in-vehicle camera is used for a certain level of adjustment so that the brightness of an image to be obtained by image pickup of the face of the driver becomes constant, as a state where outside light such as west sun streams down on the face of the driver in the vehicle arises in a complicated manner and the illuminance of the face of the driver is not constant during driving.
[Patent Document 1] Japanese Patent Application Laid-Open No. 2004-234367